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Welshite Mineral Data

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General Welshite Information

Help on Chemical  Formula: Chemical Formula: Ca4Mg9Sb3O4[Si6Be3AlFe2O36]
Help on Composition: Composition: Molecular Weight = 1,746.53 gm
   Calcium     8.74 %  Ca   12.23 % CaO
   Magnesium  10.91 %  Mg   18.09 % MgO
   Manganese   3.68 %  Mn    4.75 % MnO
   Beryllium   1.67 %  Be    4.64 % BeO
   Aluminum    2.38 %  Al    4.50 % Al2O3
   Zinc        0.15 %  Zn    0.19 % ZnO
   Iron        4.16 %  Fe    0.21 % FeO /  5.71 % Fe2O3
   Silicon     8.96 %  Si   19.16 % SiO2
   Antimony   21.12 %  Sb   28.06 % Sb2O5
   Arsenic     1.59 %  As    2.43 % As2O5
   Oxygen     36.64 %  O
             ______        ______ 
             100.00 %       99.98 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Be3.24
Help on IMA Status: IMA Status: Approved IMA 1978
Help on Locality: Locality: Langban, Varmland, Sweden. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Wilfred R. Welsh (1915-?), amateur mineralogist and teacher of natural sciences.
Help on Name Pronunciation: Name Pronunciation: Welshite Say WELSHITE

Welshite Image

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Comments: Deep red, prismatic crystal of welshite in matrix.
Location: Langban, Varmland, Sweden. Scale: Crystal size 1.5 mm.
© Tom Loomis / Dakota Matrix

Welshite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.9644:1:0.8254
Help on Cell Dimensions: Cell Dimensions: a = 10.394, b = 10.777, c = 8.896, Z = 1; alpha = 105.953°, beta = 96.294°, gamma = 124.948° V = 780.61 Den(Calc)= 3.72
Help on Crystal System: Crystal System: Triclinic - Pedial H-M Symbol (1) Space Group: P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.53(1), 2.91(0.7), 7.324(0.7),

Physical Properties of Welshite

Help on Cleavage: Cleavage: None
Help on Color: Color: Brown, Reddish black, Orange brown, Deep tan.
Help on Density: Density: 3.77
Help on Diaphaneity: Diaphaneity: Subtranslucent to Opaque
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 6 - Orthoclase
Help on Luster: Luster: Subadamantine
Help on Streak: Streak: light brown

Optical Properties of Welshite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.099 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.057 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2083,KPDmeas= 0.2166,KC= 0.1971
Ncalc = 1.74 - 1.77
Help on Optical Data: Optical Data: Biaxial (+/-), a=1.81, b=1.81, g=1.83, bire=0.0200, 2V(Calc)=0, 2V(Meas)=45.
Help on Pleochroism (x): Pleochroism (x): none.
Help on Pleochroism (y): Pleochroism (y): none.
Help on Pleochroism (z): Pleochroism (z): nnone.

Calculated Properties of Welshite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.74 gm/cc
note: Specific Gravity of Welshite =3.92 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.03
Boson Index = 0.97
Help on Photoelectric: Photoelectric: PEWelshite = 70.38 barns/electron
U=PEWelshite x rElectron Density= 262.93 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Welshite is Not Radioactive

Welshite Classification

Help on  Dana Class: Dana Class: 69.02.01a.07 (69)Inosilicate Chains with Side Branches or Loops
  (69.02)with P>2
  (69.02.01a)Aenigmatite and related species (Aenigmatite subgroup)
69.02.01a.01 Aenigmatite (Na,Ca)4(Fe,Ti,Mg)12Si12O40 P1 1
69.02.01a.02 Dorrite Ca2Mg2Fe4(Al,Fe)4Si2O20 P1,P 1 Tri
69.02.01a.03 Hogtuvaite (Ca,Na)2(Fe,Fe,Ti,Mg,Mn)6(Si,Be,Al)6O20 P1 1
69.02.01a.04 Krinovite NaMg2CrSi3O10 P1 1
69.02.01a.05 Rhonite Ca2(Mg,Fe,Fe,Ti)6(Si,Al)6O20 P1 1
69.02.01a.06 Serendibite Ca2(Mg,Al)6(Si,Al,B)6O20 P1 1
69.02.01a.07 Welshite Ca4Mg9Sb3O4[Si6Be3AlFe2O36] P1 1
69.02.01a.08 Wilkinsonite Na2Fe4Fe2Si6O20 P1 1
69.02.01a.09 Makarochkinite! Ca2Fe4FeTiSi4BeAlO20 P1 1
Help on  Strunz Class: Strunz Class: 09.DH.45 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DH -Inosilicates with 4-periodic single chains, Si4O12
09.DH.45 Aenigmatite (Na,Ca)4(Fe,Ti,Mg)12Si12O40 P1 1
09.DH.45 Dorrite Ca2Mg2Fe4(Al,Fe)4Si2O20 P1,P 1 Tri
09.DH.45 Krinovite NaMg2CrSi3O10 P1 1
09.DH.45 Rhonite Ca2(Mg,Fe,Fe,Ti)6(Si,Al)6O20 P1 1
09.DH.45 Sapphirine (Mg,Al)8(Al,Si)6O20 P1 1
09.DH.45 Serendibite Ca2(Mg,Al)6(Si,Al,B)6O20 P1 1
09.DH.45 Khmaralite! (Mg,Al,Fe)16(Al,Si,Be)12O40 P 21/c 2/m
09.DH.45 Makarochkinite! Ca2Fe4FeTiSi4BeAlO20 P1 1
09.DH.45 Welshite Ca4Mg9Sb3O4[Si6Be3AlFe2O36] P1 1
09.DH.45 Wilkinsonite Na2Fe4Fe2Si6O20 P1 1

Other Welshite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(AmMin, V87:358 and v92:80) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Welshite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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Dana No: 69.02.01a.07 Strunz No: 09.DH.45





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